Searching for a Surround Sound Audio Console

With NAB2007 fast approaching, here are some tips to help in your search for a surround sound mixing system.

Even with the crowds, NAB can provide a good opportunity to check out the various systems that are available and compare and contrast. Often on Wednesday and even moreso on Thursday, the crowds around the consoles usually thin out enough to make it easier to take a test drive.

But it's still best to schedule an appointment no matter what day you visit, to make sure that there is someone there with the time to give you a detailed demonstration of the console and to answer your questions.

BE PREPARED

Before heading out to the Las Vegas Convention Center, take stock of what equipment has to be connected to the new console, and how many audio inputs and outputs each piece of gear has. What format are those I/Os? Analog (balanced or unbalanced) or digital (AES-3, AES-3id, S/PDIF, MADI, SD-SDI and HD-SDI embedded, Dolby E)?

Estimate your future equipment plans, like HD video servers that can provide more audio channels than two or four per video channel.

Will you need remotely controlled stage boxes for microphones and line-level feeds (send and receive)?

Poll the audio operators about what they would like to see. What works well in the console or consoles you now have? What could be improved? Especially if this is your first foray into digital audio mixing systems, what are the operators' concerns about moving from analog to digital? These are good topics to bring up with the console vendors that you visit. How they address these concerns can help you winnow down your choices.

How much physical space do you have for the console control surface? And how good is the access to the audio control room? Will elevator, corridor or door sizes limit the size of the control surface rather than the room size?

Familiarize yourselves with the various console vendors by looking at their Web sites and requesting and reading their literature.

Then choose the ones you wish to visit at NAB. When you make your NAB appointments, also ask for a full customer list of current users. Call some of these references before NAB to find out how well things have worked out with their installations. What would they have done differently? How easy was it for their operators to come up to speed on the new board? How good were manufacturer's training, service, and general responsiveness? Are there any outstanding issues with the performance of the console or the manufacturer?

Internet user groups for a particular product can also provide enlightening insights about how a system really performs.

The more informed you are going into your meetings or demos the better.

BE INQUISITIVE

Then its showtime in Las Vegas--time for hands-on demonstrations with your choice of manufacturers.

Discuss your particular show requirements for a typical production like evening news and a more complex one like election night coverage. How well can the console perform the tasks you need it to do?

It's important to get in front of the console to see how it feels ergonomically. Is it easy and comfortable to operate? Can you see and reach all the controls easily, especially if you are in a hurry to make a quick adjustment? Can you clearly see the meters and screens from both a sitting and a standing position? Is there a preferred chair height for operating the console? Does the layout minimize visual fatigue? Keep in mind that someone may have to sit in front of the console for a long time on some shows.

At NAB, you won't be able to control the ambient lighting of the booths, but keep in mind the ambient lighting of your control rooms. Will the displays be readable in low light?

Go through all the workings of the console from inputs to outputs.

How does the system handle multiple sources per input device? For example, can one fader be used to control a 5.1 source or do you need three stereo or six mono faders, or groups to handle this? How do you make an input channel mono, stereo, or 5.1 (or other), if the console has this capability? If layering is used on the mixing system, how easy is it to find the sources you're looking for and to make adjustments to them?

Find out how to set such parameters as mic and line gain, dynamics, EQ, delay and panning, and how that might differ between stereo and 5.1, for example. Learn how to set up output routing, mix-minus feeds, talkback, and pre-fade or after-fade listens.

What are the maximum limits to the various settings? (For example, what is the maximum amount of delay per channel?)

Consider the advantages and disadvantages of different system architecture such as layering or not, and in-line controls for all parameters on each channel strip or a centralized control panel with maybe some assignable controls for the most used parameters.

How many group, auxiliary, and main outputs are available? How are sources routed to these various outputs?

How are mix-minus feeds derived? For example can both additive and subtractive mix-minus feeds be created? How does this meet with your production requirements? How quickly can the sources to the mix-minus feeds be changed once the show is on-air?

How does the system handle insert sends and returns to external processing devices?

How extensive is the monitoring section? Are there provisions to monitor the various downmixes and surround encoders?

Will you need to produce simultaneous outputs in multiple formats, like stereo and 5.1, full program and international feeds? How does the console support this?

What kind of metering is offered as standard and as options? Is this adequate for your needs?

Digital mixing systems rely on DSP or digital signal processing to perform its functions. Is there enough DSP for all channels simultaneously or is DSP shared among channels? If the latter, at what point does the DSP max out?

What settings can be saved and recalled and how do you do that? Can you develop show presets and save snapshots?

Do you need machine control for such equipment as recording devices or special effects units? Does the console provide any?

ASK FOR A DEMO

Ask for a demo on how to configure the mixing system. Is the configuration process easy and versatile? How are repetitive tasks handled (like setting up multiple channels the same way)? Is there an alphanumeric display for labeling sources and destinations? How many characters? Will this be enough for your labeling scheme?

Can busses be easily re-assigned in case of a problem while on-air?

Look at the physical characteristics, system architecture, and networking.

Will the system handle the number and format of inputs and outputs you need, now and in the future? Is the system AES48-2005 compliant?

It's been two years since the ratification of this AES standard for grounding and EMC practices regarding connector shields, so I think it's a fair question to ask any manufacturer of products containing audio inputs and/or outputs.

How easy will it be to expand in the future? What is the future-proofing philosophy of the manufacturer? Make sure the board you buy has a development future that can cope with your growth and changing needs.

How much space does the central electronics frame(s), and power supplies occupy? Don't forget the power supply for the control surface. Are there any special HVAC requirements? Are rack-mounted cooling fans needed? What is the maximum length for control and power supply cables from the electronics frame to the control surface?

What sizes of control surfaces are available, in terms of physical dimensions and number of faders?

It's a good idea to have some idea of how many faders you think you'll need, but wait and see how the console deals with multiple audio feeds from a single source before you finalize that requirement. You may find that due to console architecture you can work with less faders than you originally thought.

Does the audio mixing system need to interface with your plant router? How well can it do it? Can it call up sources directly, including mnemonics?

Will the digital audio mixing system need to serve more than one studio and audio control room? Can the system be designed to share common resources? Ask for specifics.

Networking can save on installation costs, and potentially allow for easier future expansion.

Many audio mixing systems offer an audio routing switcher or some other kind of distributed routing scheme to share resources among control surfaces. This could be sufficient for the audio section of a larger plant routing system in some facilities. Will this work at your place?

How well can the audio router communicate with your plant router control system? For example, if when a source is selected, can it display the proper information on the control surface?

For a mixing system for live productions, redundancy is important. What redundancies are provided (or can be provided as an option) in the system, for example power supplies, DSP cards, or system controllers? Ask for a demo to see what happens if a power supply or DSP card goes down or is pulled out. Is the backup automatically switched in? Is there any interruption in operation?

Can channel strips on the control surface or cards in the electronics chassis be hot-swapped? Try it.

If the system should totally go down, how long does it take to reboot? Ask the manufacturer to demonstrate.

Some general comments. Don't be impressed with the first mixing system you see. Reserve judgment until you've seen a few. Make notes after each demo, and compare features, pros and cons.

As you narrow your selection, you will probably have further questions, so make sure you get the contact information of the person doing the demo and your local rep. As the time for final decision nears, ask for a post-NAB demo at your facility or somewhere nearby.